A known cellular communication network employs so called network assisted D2D communication, also referred to as Machine-to-Machine (M2M) communication, between user equipments. Thanks to the D2D communication, load on the cellular communication network may be reduced. The load can be measured in terms of for example radio resource usage, traffic between a base station and a user equipment. In particular, load on the radio base station, comprised in the cellular communication network, may be reduced.
With the network assisted D2D communication, two user equipments are allowed to use licensed spectrum resources to communicate directly with one another via a so called D2D link. In contrast, with cellular communication methods, data is transmitted between the two user equipments via the radio base station. The D2D link connects the two user equipments directly, without passing user data via the radio base station. Hence, the radio base station is off loaded.
After the D2D link has been established, the two user equipments may control power for transmission on the D2D link in order to ensure that the D2D link remains reliable. However, since the two user equipments may move around, the D2D link may degenerate. Moreover, the two user equipments may cause other links of the cellular communication network to degenerate.
US2011/0312331 discloses a method for resources scheduling for network controlled D2D communications. A network node obtains a reference point with a fluctuation range based on at least one metric for a plurality of cellular user equipments and at least a pair of device-to-device (D2D) user equipments. The network node signals the reference point and the fluctuation range to the pair of D2D user equipments. Then, the network node allocates radio resources to the pair of D2D user equipments. Furthermore, the network node receives metric updates from the pair of D2D user equipments and the plurality of cellular user equipments. Next, the network node adjusts the reference point and the fluctuation range according to the received metric updates.
Disadvantageously, the D2D communication may degenerate as the pair of D2D user equipments move around.